Brother (Mine)
by TheMadKatter13
Summary: Any good little brother would do anything for their older brother. And Ritsu is a /very/ good little brother. AU; Top Alpha Ritsu / Bottom Omega Mob
1. Nightmare

**SUMMARY: Any good little brother would do anything for their older brother. And Ritsu is a _very_ good little brother.**

**AO3 TAGS: Alternate Universe, Alternate Universe - Canon Divergence, Omega Verse, Alpha/Omega, Alpha/Beta/Omega Dynamics, Alpha Kageyama Ritsu, Omega Kageyama "Mob" Shigeo, Possessive Kageyama Ritsu, Pre-Awakening, Non-Powered Kageyama Ritsu, Underage Kageyama Ritsu, Underage Kageyama "Mob" Shigeo, Incest, Sibling Incest, Brother/Brother Incest, Underage Sex, Consensual Underage Sex, Top Kageyama Ritsu, Bottom Kageyama "Mob" Shigeo, Anal, Anal Sex, Knotting, Established Relationship, Plot What Plot/Porn Without Plot**

**AN: *watches Voltron***  
***starts Voltron fic***  
***watches Naruto***  
***stops writing Voltron fic to start Naruto fic***  
***watches MP100***  
***stops writing Naruto fic to write MP100 fic***  
**someone save my WIPs from me**

**I never go into a new fandom looking to ship something, and yet, here I am. I can't even remember what it was, I just remember Ritsu doing or saying something and I was slapped with the need for possessive Ritsu… help…**

**EDIT: Original summary was moved to the c1 Summary when I added a second chapter to make way for an overall fic-themed summary.**

* * *

**CHATPER SUMMARY: "I dreamed that I'd taken a different route home today," Ritsu confessed, trying to remain calm, trying to keep the roll of hips, the glide of his cock in and out of his brother, smooth and even. He could still see those alpha's faces in his mind, could still remember the way _his_ omega has smelled, wrapped in their faint scents. "That I never saw you with those alphas, that they took you away and had their way with you. That they took you from me."**

* * *

CHAPTER 1 - NIGHTMARE

"Aren't you an adorable omega?"

"Maybe you can help us find someone, cutie."

"Maybe we can make it with your while…"

It was easy to find the source of the catcalls - almost every person in the plaza was moving towards their destination except for a small group of boys wearing Miso Middle School uniforms standing in a half circle. Ritsu suppressed a sigh of annoyance and moved towards them to make sure the omega didn't need any help.

"Yeah, have you heard of White T Poison? We know he goes to Salt-"

There was a suspicious sinking feeling in Ritsu's belly and he started to jog, nose lifted into the air, trying to catch the scent that he just _knew_ was going to be there. He circled around the outside of the boys - there was only four of them - and found an opening. An opening where Mob's familiar form was standing, head tilted back to look the taller alphas in their faces.

All four boys were leaning too far into Mob's space, their scents unchecked in the air, clinging to Ritsu's brother. And Mob was just standing there, posture, face, and scent relaxed, no hint of rejection or even challenge. For all that Mob was the most powerful person Ritsu knew, possibly the most powerful person ever, he was also the person least likely to use that power, especially on another person. And yet, it was as if every evolutionary instinct bred into omegas had just skipped his older brother entirely - Mob wouldn't protect himself if his life counted on it. That was alright - that's what Mob had Ritsu for.

"Why don't you come with us and we'll show you what White T Poison did? A little demonstration? Maybe that'll help you help us."

Mob - gentle, innocent, _naive_ Mob - nodded his head as he stepped forward. "Okay."

Possessive fury ripped through Ritsu and he clenched his jaw tight, trying to keep it inside as he stepped up behind his brother, stopping his forward momentum with an arm around his shoulders and across his chest. "Nii-san."

"Ah," Mob murmured in his own soft brand of surprise. "Ritsu."

Something in his scent, something small, almost imperceptible, even to Ritsu, who had spent his whole life with Mob, shifted as Mob relaxed back into Ritsu's chest. The furl of fury in Ritsu's chest loosened at his brother's easy acceptance of his claim and he let his scent wrap around his brother, banishing the weak scent-claims of the strange alphas.

Ritsu turned his glare on them, holding Mob tighter. "What did you need from my nii-san?"

If they really wanted Mob, they could have fought Ritsu for him, but the only thing worse than trying to fight a mated alpha was trying to fight a familial alpha. Mob may have had to look up a handful of centimeters to be able to make eye contact with the alphas, but Ritsu could stare them down head-on, and though they might have had more experience, and more fighters, than Ritsu, it was clear none of them wanted to pick a fight in a physical space. Especially not over a single omega.

One of the alphas, the one who had been closest to Mob, the one who'd been the closest to touching Mob, bit out a "Tch-" and leaned back, and the other three followed suit. "Nevermind," he nearly growled before turning sharply and striding away. His friends looked after him, looked at Ritsu, then back to their leader before scampering to follow.

It only took a minute before they were out of sight, taking their disgruntled pheromone trails with them, and it was only then that Ritsu relaxed, pulling away to step up aside his brother. He left his arm across Mob's back, his hand on Mob's shoulder, a claiming touch, and smiled down at Mob.

"Alright, Nii-san?" he asked, smiling gently.

Mob smiled back, a small, soft little thing that was only for Ritsu, a tiny shift of facial muscles but enough to make that possession curl into a black little ball in Ritsu's heart. "Yes, thank you, Ritsu." He looked away towards the alphas. "I hope they find who they were looking for."

Ritsu blinked, and then he laughed. Powerful, naive Mob. Beloved, unselfish Nii-san. "Let's go home."

* * *

Ritsu bolted upright, panting hard into the silence of his bedroom. The sudden departure from his dreams left him disoriented, and it took a few moments to realize he was growling, his teeth sharp in his lip, his pheromones out of control in the small room. He forced himself to breathe steady, to calm his heart and bring his scent back under control, but even as the clock on his nightstand ticked closer to morning, he couldn't quite shake the emotions that had force him awake.

He paused outside of his parent's room, listening hard, before creeping across the hall to Mob's room, the door opening silently under his hand. "Nii-san? You awake?" he whispered into the dark. There was no response, and after a few moments, his eyes adjusted to the pale moonlight barely illuminating the room.

Mob's futon was slightly off to the side, his brother's body a nearly-indistinguishable lump of blankets. Ritsu had never understood why his brother had rejected a more western bed like he and their parents had, and he'd always wondered if it was another manifestation of his brother's almost-unreasonable unselfishness. Mob didn't stir until Ritsu was sliding under the covers, pressing up tight against his older brother's smaller back.

"Ritsu?" The soft sound was a sleepy slur, the turn of Mob's head even sleepier, nose brushing along the line of Ritsu's jaw, a sweet, barely awake scenting. "Sfrbl… 'ay?"

"Nightmare, nii-san," Ritsu whispered back, pressing a smile into the side of Mob's neck.

His older brother hummed and tilted his head away, exposing more of his neck for Ritsu, inviting the gentle scrape of teeth. Ritsu shushed him even as he wrapped an arm around Mob's waist and slid his hand into Mob's sleep pants. His omega's cock was already hardening, and endulated into the easy, exploratory pressure of his fingers. He indulged only for a few moments, stroking Mob to hardness, before he slowly pulled his hand back and began to push at Mob's pants. The omega lifted his hips, sleep-numbed hands almost hindering the progress Ritsu was making rather than assisting, but finally Mob's pants were around his knees.

The blanket shifted when Ritsu pushed his own pants down, and the sweet scent of omega arousal drifted out to his nose, making his cock throb. Sometimes Ritsu wondered if it was some part of his brother's psychic powers affecting his scent, or if that's how he would smell even if he'd been born powerless. There was none of heady, saccharine lure as was common in omegas prone to domesticity, nor was there the spicy, mouth-watering temptation of adventure-driven omegas. No, Mob had to be different there too - his scent wasn't exactly a scent, but rather something akin to what Ritsu thought a cat laying on fresh laundry in the sun might feel like.

Ritsu pressed his fingers into where Mob was already wet, more so that he could immediately put them against his tongue and lick them free of slick than to test if Mob was loose enough - he was always loose enough, he was always ready to take Ritsu when Ritsu needed to take him. The second time he pushed his fingers into his brother's welcome heat, he had to force himself not to put them back in his mouth, but to use them to slick his cock.

Mob's body opened around him, pulling him in, and Ritsu carefully pressed his teeth to his brother's neck, careful not to break skin and careful not to make a sound. He never had to worry about Mob making a sound, his brother was as quiet in sex as he was in life, but there was a feeling in the air like lightning about to strike. After Ritsu fell still with his hips pressed to Mob's ass, the barely-yet-there swelling of his knot wrapped tight in slick heat, he smoothed his damp hand up his brother's chest to gently grip Mob's jaw and turn his mouth into Ritsu's. The kiss was forcibly soft and gentle, carefully done to calm Mob's heart and his mood, to sieve the sensation of lightning from the air.

Ritsu had only seen his brother loose control once, and it had terrified him - not because he feared for himself, but because he feared for his brother. At that time, it had been in his defense, and he'd been protected and safe, both from the older boys and his brother, but he wasn't sure that who, or _what_, had saved him had been his Mob. Ritsu had always done what he could to keep his beloved nii-san happy, but he'd always been extra careful after that, petrified that that other being would replace Mob and he'd lose who he loved most. There was no telling if Mob would break in that same way if he lost control while Ritsu was inside of him, so as always, Ritsu would protect his brother when he couldn't protect himself.

"What- what was your nightmare about, Ritsu?" Mob rasped against Ritsu's lips, eyes half-lidded and body relaxed in Ritsu's embrace and around his cock.

Ritsu pressed a last chaste kiss to Mob's cheek before reaching down to hook his fingers behind the knee of Mob's top leg, pulling it up the futon, forcing Mob more onto his chest and opening him further. Mob's eyes fluttered, and then closed entirely when Ritsu, leaning into the warmth of his older brother and balanced on his elbow, rocked out and back in. The sensation sent heat through Ritsu's groin and up his spine, and he had to lean down to press his face to his brother's neck again, breathe right into where mating mark was supposed to go. Where Ritsu's mark could never be, but it was a daydream that he returned to time and time again, regardless. Some days, it was all Ritsu could do to push down the burning desire to sink his teeth in the delicate skin at the back of his brother's neck and fuck the consequences.

"I dreamed that I'd taken a different route home today," Ritsu confessed, trying to remain calm, trying to keep the roll of hips, the glide of his cock in and out of his brother, smooth and even. He could still see those alpha's faces in his mind, could still remember the way _his_ omega has smelled, wrapped in their faint scents. "That I never saw you with those alphas, that they took you away and had their way with you. That they took you from me."

Despite his efforts, rage filled him and the air again, made his steady rhythm falter when he jerked forward a little too hard, made his teeth a little too sharp. Mob's breath hitched, his body paused a moment almost too long, and then he lifted his hips into Ritsu's harsher rhythm. Ritsu's knot was slowly expanding as the heat in his groin grew, but Mob's body easily took it under the force of his sharp thrusts. Ritsu had to turn his head into his brother's pillow to breathe in the ingrained scent, and keep himself from biting into the back of Mob's neck, his breaths exaggeratedly steady until his hips stilled.

"Ritsu," Mob whispered, voice wavering, and it was that waver that helped Ritsu pull himself together.

Ever since his brother had closed himself off from his own emotions, ever since he had affectated the blank state he now lived in, the tiniest little thing could be an indicator of his mood. Most rarely it was a shift in that soft, comforting scent, sometimes it was a tension in Mob's voice or body, but usually it was the smallest hint of an expression, pulling at unused facial muscles. Now, as Ritsu renewed his control on himself, he could see the tension at the corners of his nii-san's eyes and the slight wobble to his lips, could feel the tremor in the smaller body under his, could scent the faint call of _need_ in the air. He had to calm down and focus, for Mob, if not himself.

"Sorry," he murmured, leaning over Mob to nuzzle gently at his jawline. He let the sweet but faint scent of omega arousal relax him until he was half laying on his brother, cock hard but still in the pulsing heat. "I'm sorry, nii-san. Didn't mean to lose control. I just can't stand the thought of you being taken from me."

His omega's cock was small but hard, and Ritus carefully, gently cupped it in his hand, pressing it to his brother's belly. Leaning up on his elbow over Mob, Ritsu had the perfect view to see when Mob's eyes fluttered at his touch, to see when his chest froze and then juddered as his brother fought for self control. When Ritsu pulled out and then pushed back in, stroking down Mob's cock, Mob's eyes fell closed, his eyelashes like shadows. He pressed a soft kiss to Mob's temple as he fell into the steady rhythm, careful not to let his emotions disrupt the beat. Even the wet sounds of his cock pushing in and pulling out of his brother were muted.

"I-" Mob started and then stopped, mouth opening and closing as he tried to find his words. Ritsu nuzzled at his hairline in silent encouragement. "I will always be here for you, Ritsu."

Hunger flashed through Ritsu, sharp and hot, and he had to swallow hard against the sudden influx of saliva in his mouth. His teeth almost ached with the need to sink into flesh, and his heart echoed the desire to bond them. His knot was starting to throb, his balls drawing up tight."I know, nii-san. I hope you never forget the reverse is also true."

At that, the corner of Mob's mouth twitched, a phantom of that smile-just-for-Ritsu. "I know."

It was that small, almost-smile that did it, that sent that heat in his spine rushing through and out him. Ritsu carefully set his teeth to the cloth-covered curve of Mob's shoulder as he firmly and steadily forced his knot into his brother, breathing out as he came and expanded into the come-soaked heat. Under the unyielding press of his hips against Mob's ass, the force of his knot against Mob's prostate, and the curve of his fingers around Mob's cock, his omega started to come too.

Something in the air broke, a tension Ritsu hadn't even noticed had been building, as wet spilled into Ritsu's hand and the muscles around his cock started to spasm, milking him of seed that would find no home, if only because his older brother was so careful with his birth control. He could even feel the beat of Mob's heart around his cock, and his own was a thumping echo he could feel through his whole body.

The pleasure, as always, was slow to fade, even if it was only because his swollen knot tied them together, keeping him inside that delicious burning heat and sending frissions of lava up his spine if he did more than simply breathe. The air was saturated with the scent of their sex, and even though he'd just come, it effortlessly reignited Ritsu's hunger for his omega, made him throb inside of Mob. Mob shifted with a soft sound, one too soft for Ritsu to decipher, and Ritsu finally lifted his cupped hand from the soft cock, bringing it to his mouth to lick clean.

"Ritsu…" Mob sighed into the quiet room. His body was as it always was, soft and pliant against Ritsu's, but after Ritsu knotted him, he was always just a little more boneless, a little more malleable.

"Yes, nii-san?" he whispered back, mouth filled with his brother's taste - it wasn't as addictive as the taste of Mob's slick, but it still helped eased his near-insatiable and unending craving.

Mob was silent for too long, long enough for Ritsu to be satisfied that he'd lapped it all up before wrapping an arm around Mob's waist. He curled up tight around his brother, half wondering if Mob was always going to be shorter than him. The shift sent muscles rippling around his sensitive cock, and for a moment, Ritsu's hold went a little too tight, until a gentle hand stroking his fingers helped him relax. Mob still hadn't answered.

"Are you alright, nii-san?" he asked worriedly, sliding his hand up Mob's chest to press against his heart. He could still feel Mob's steady heart rate against his cock, but he'd found that the touch helped to ground his brother.

"Mm," Mob finally hummed with a small nod. "I was just wondering…"

He trailed off again and Ritsu suppressed a sigh. Even if his brother was bleeding out, he would hesitate to ask for help.

"Ask me anything, nii-san," Ritsu encouraged, emphasizing the sentiment with a soft, reassuring growl.

"My next heat is during okaa-san and otou-san's vacation."

It wasn't so much a question as a reminder, but Ritsu heard the supplication as if it had been shouted at him. He forced his lungs to continue at a steady pace, forced his body not to curl tight like a cage around his brother, forced the alpha side of himself - the side that wanted to claw and bite and mark - into submission, and pressed a soft kiss to the curve of his omega's neck. Mob, tempting fate, sighed softly and trembled in Ritsu's arm, back arching into Ritsu's chest, ass gripping Ritsu's cock so tight it was as if Mob would never let go.

"Don't worry, nii-san," Ritsu whispered, mind aflame with the memory of the last time he'd satisfied Mob's heat, so long ago. Too long ago. The knowledge that his brother wanted him for his next heat would haunt him for the next several weeks, would keep him distracted during student council meetings and keep him awake at night. It was going to be well worth it. "I'll take care of you."

FIN

* * *

**"I probably won't be writing any more for this ship/fandom," she says, knowing full well that she can never plan for such things.**

**Btw, if you haven't seen liieyn (on tumblr)'s RitsuMob art, you're missing out - it's so soft~**

**Like the thing? Reblog the thing (themadkatter13fanfiction tumblr, tagged/Brother (Mine)).**


	2. Stress

**Guess which dumbass saw a super cute art on twitter (twitter, zer0zon/status/1104602941451722752) and is now writing more for a ship no one is interested in reading~ :D**

**Also seeing that and writing this means I realized that I may be adding random timestamps to this fic here and there rather than doing any sequel(s) as New Story(s).**

**'Abricate' is an old word that means 'basking in the sun'. I went looking for a word that meant that when I was trying to find a title for the original fic, expecting there to be a weirdly specific German word for it or something, and imagine my surprise when I found an English one!**

* * *

**CHAPTER SUMMARY: Before Ritsu could speak, Mob was crawling right into his lap and face-planting in his neck, blanket settling over Ritsu's legs.**

**ADDED TAGS: Timestamp, Time Skips, Psychic Abilities, Psychic Kageyama Ritsu, Awakened Kageyama Ritsu, Powered Kageyama Ritsu, Psychic Sex, Sex Magic**

* * *

CHAPTER 2 - STRESS

Some part of Ritsu has always just _known_ when his brother got home. Before his powers woke, before he presented alpha, some part of him had just _known_, even if he hadn't understood how he'd known. In the years since his powers had awakened though, he'd come to understand that every fiber of his being was simply attuned to Mob's powers, and that he'd been able to sense his brother's aura washing over him. He could feel it now, could feel the way it touched upon everyone and everything in their house, a reflex to make sure everything is as it was. As had been habit for the last several years, his immediate reaction was to return the gesture, but before he could, Mob retreated, his aura neatly packing away.

Ritsu sat upright, immediately on guard, book in his hand forgotten. His eyes fixed on his open door, waiting, watching. Mob appeared after a minute, trudging up the stairs in his slippers, head down.

"Nii-" Ritsu started to call out, but Mob didn't even look at him as he shuffled by. He frowned at the empty doorway, and was still frowning when their mother came up, pausing at the top of the stairs and frowning down the hallway. Which means that Mob hadn't acknowledged her either.

She turned and looked at Ritsu, a silent question, and he shrugged, just as lost. He hadn't heard from Mob all day and as far as he knew, there wasn't anything going on in his brother's life of late that warranted this kind of reaction. Her head turned a moment later at the sound of a door opening, her mouth opening like she was going to speak, but Mob walked right by her, shuffling into Ritsu's room in shorts and a t-shirt, trailing a blanket. Before Ritsu could speak, Mob was crawling right into his lap and face-planting in his neck, blanket settling over Ritsu's legs.

Ritsu looked at their mother, who was making an enthusiastic 'go on' gesture, and then down at his brother. "Are you alright, nii-san?" he asked softly.

He tried to scent the air, hoping to catch a whiff of his brother's mood, but Mob had hidden his scent along with his aura, and it was almost like he wasn't there. The alpha part of Ritsu was restless at the absence of scent when he had his omega sitting right there in his lap, but the logical part of him was well used to it. His brother had gotten a lot better about letting himself feel and emote in recent years, even as his powers continued to grow, but he'd grown up hiding himself and sometimes he still had trouble with it.

There was a deep inhale at his throat, a pause, and then a slow exhale. A barely-there shake of Mob's head.

Ritsu looked back at his mother and frowned when he saw her straighten almost unnaturally. And then he saw the dead look in her eye and the slackness to her jaw before she turned and walked silently back down the stairs. Like a marionette. Stunned, he looked back down at his brother. This was… unprecedented. Mob _never_ used his powers on their parents.

"Do you need me, nii-san?" he asked, slowly raising his hand and tentatively cupping the back of Mob's neck.

There was another pause, and then he felt his brother nod. Just barely, but it was there. And for it to be there at all meant, for Mob to be so closed off and not speaking, for Mob to have used his powers on their parents, meant that he was hanging on by a thread.

"I've got you, nii-san," Ritsu assured, tightening his hold on the back of his brother's neck, the firm hold making Mob relax just a little more against him.

Ritsu had hit his growth spurt his third year of middle school, and now he was even taller than their father, but Mob never seemed to really hit his. He'd grown steadily a centimeter or so every year, but his head had never even reached Ritsu's shoulder. Mob had never given any indication if he was displeased by his younger brother growing so much taller than him, but Ritsu's alpha side was continuously pleased by their height difference, the way his omega fit so neatly against him.

The book in his hand went face down on his desk and Ritsu carefully lifted Mob with the help of his powers, raising him off his lap so he could undo his jeans and stroke his cock to life. When he reached for the waistband of Mob's shorts, a tendril of power breezed across the head of his cock and there was a shift of air before he felt the heat of Mob's hole. The seat of his brother's shorts had been neatly unthreaded at the seem, and though it made for convenience, the use of power for something so trivial only served to increase Ritsu's concern.

He slowly lowered Mob onto his cock and back into his lap, and found himself sighing at the relaxing sensation of wet heat wrapping around him. It was almost like coming home, for Mob's body had been a source of comfort for Ritsu his whole life. He wondered sometimes what their relationship would have been like had Mob been born powerless - would they have ended up in love at all? Would their love been as passionate and energetic as most alpha/omega relationships were? He had no way of knowing, and though he wondered, he never missed what they never had. Some alphas might revel in their fiery relationships, but Ritsu liked the calm that came with being with Mob.

The blanket over his legs had slipped and he drew it back up over Mob's waist and tucking it behind him between his back and the back of his chair. Just in case Mob's powers wavered and either of their parents came back. It was unlikely, but still, they hadn't remained undiscovered for this long because they lacked caution. It was good fortune as it was that so many omega siblings found tactile comfort in their alpha siblings, and vice versa, even long into adulthood - no one would ever think twice about Mob cuddling with him or with him scenting his brother, as long as he didn't take too long doing it.

Mob hadn't moved from his slouch against Ritsu's chest, and his breathing was steady, but his cock was slowly hardening against Ritsu's belly. Ritsu squeezed the back of his neck once and then started to gently stroke Mob's back, encouraging him to relax. Long minutes passed, but there was still a tension to Mob. No one else would have been able to tell but Ritsu, not even their parents. But their parents hadn't spent their whole lives looking out for Mob, hadn't spent years knotting Mob in the dead of night or during Mob's heats when the house was empty.

"Do you need my knot, nii-san?" he finally asked. It was a last resort for the situation, especially since their parents were home, even if they were currently under the influence of Mob's powers. But Mob still hadn't relaxed and he was still holding his aura and scent locked inside his skin.

He didn't get a nod this time, but the mouth at his neck parted and he felt the barest of touches of the tip of Mob's tongue to his skin and heat flashed through his body, his cock suddenly throbbing with need.

"Of course, nii-san."

It was going to be an even less conventional coupling than usual, but he'd spent his life striving for his brother's happiness because when Mob was happy, Ritsu was happy. He'd never used his powers like this before, but there was a first for everything. And the first stroke of his powers around their cocks had white fuzz rolling up his spine and Mob inhaling against his throat. Ritsu dipped his head to his brother's neck and nipped gently at the soft skin as he did it against, and he felt satisfaction curl in his chest at the tremor that went through Mob.

Fucking his brother without moving a muscle was an odd sensation, but there was something so comforting about it, about being able to wrap his arms around his brother and get them off without having to separate from him for even a second. With every stroke of his powers he could feel his knot starting to swell, but more importantly, he could feel the way Mob shivered with every phantom touch. He could feel the way that vague almost-undetectable tension in his omega's smaller body start to unspool. And because he didn't have to move his face from Mob's neck, because he didn't have to move his nose from Mob's scent gland, he could scent the very second Mob's scent started to return to his skin.

The first whiff of that familiar scent of abrication set off a pleased growl in Ritsu's chest, and he got to feel the moment it hit Mob - a sharp stuttered inhale against his neck and a sudden clench of muscles around the length of his cock. But then the subtleties of emotion tainting the sun hit him and he went tense at the faint threads of stress in his omega's scent. He began to purr in earnest, pushing as much 'comfort' into his scent and aura as he could, not letting up even when he felt a soft sigh against his throat.

It was tempting, to remain this way, to keep Mob in his lap as he stroked them with his powers, keeping them on the edge of orgasm as afternoon gave way to evening, but this wasn't for him, this was for Mob. And he knew Mob wasn't going to fully relax until he was knotted and filled with Ritsu's come. He slowly increased the grip and speed of his powers, carefully keeping the pace from becoming to fast, and when he first felt tentative whisper of Mob's aura against his, he opened his mouth and set his teeth to Mob's neck.

Just the barest hint of a bite was never enough to get Mob off, but the shortening of breaths against Ritsu's neck was like a scream of pleasure from his brother. So he carefully increased the pressure until he knew Mob's delicate skin would bruise from his mouth, hyper aware of how close he was to breaking the thin layers keeping him from Mob's scent gland. He _wanted_ to bite. He wanted to sink his fangs in and mark Mob as his - had since he presented and would until he died, but he couldn't, not until society allowed it (not that it ever would). He'd even gotten better at controlling the needs of his alpha side over the years, and he employed it now, letting the barest hint of fangs touch against Mob's skin. And _that_, _that_ was all it ever took to get Mob to come.

Ritsu's ears rang with the little whimper Mob let out against his neck as wet heat soaked the front of his shirt and he had to close his lips over his teeth to keep from biting down as Mob finally relaxed into his orgasm and into Ritsu's body. His mate's scent washed over him, through him, into him. carrying him across the finish line and into his own orgasm. He spilled into his brother's heat, his knot swelling and filling his brother full of him, a pressure against Mob's prostate making his omega shudder and come again, muscles rippling around Ritsu's cock, a familiar chain reaction that settled something in Ritsu's chest.

Sound came back to him slowly, an awareness of the silence of his room tempered by the faint sounds of their parents downstairs, the cicadas outside, the soft breaths against his neck. He barely kept himself from grimacing at the echoed thought of 'mate' - he knew it would never be, _could_ never be, but that feral part of his brain that took over when his instincts were at the helm was absolutely set on the notion. He had no idea if Mob felt the same way, and he both feared and hungered for the answer.

Mob's scent filled his lungs when he took a deep breath against his neck, and Ritsu was pleased that his brother hadn't hidden it again after he'd come. Though, that pleasure was tempered by the stress in Mob's scent, faint in the way that all his emotions were, even now. But the fact that it was there at all meant that his brother was _really_ feeling it, and Ritsu racked his brain with the potential cause.

"Would you like to talk about it?" he finally asked, pulling away from Mob's tempting throat, voice soft to keep from disrupting the room's calm. He tempered the offer with a renewal of the gentle rub of his hand in circles on Mob's back and waited to see if his brother would match his body language, waited to see if Mob would meet his eyes.

His omega shifted in his lap, not in an attempt to sit upright, but more like a little wriggle to get closer to Ritsu. It was a barely-there movement, but it was enough to send an orgasmic aftershock through Ritsu's still-hard cock and enough to make his hand twitch on Mob's back. There was just enough of a shift of the lips at Ritsu's neck and enough omega satisfaction in Mob's scent for him to know that his brother had done it on purpose, but Ritsu forced himself not to respond any further. Hs selfless-to-a-fault brother had the absolutely awful habit of deflecting inquiries of assistance when he needed them most.

Silence followed, one in which Ritsu could almost feel his brother's internal argument. All he had to do was wait it out though - once his brother stopped actively rejecting the idea of sharing a thought, it was only a matter of time until he voiced it.

"Entrance exams," he finally said, and Ritsu blinked in surprise.

Not only had he somehow not been aware that Mob was planning on attending university, but Mob had never been stressed about exams in his life. Had Ritsu been neglecting his mate- his _omega_? Had he not been paying enough attention to his brother? He would need to fix that, figure out where he'd been slacking as a brother and as an alpha, and renew his attentions. Make sure that Mob _knew_, to the bottom of his heart, that there was not _anything_ Ritsu wouldn't do for him.

"Why don't you take a nap while we wait for my knot to go down and then you can start studying with me, how does that sound, nii-san?" he offered, hoping Mob wouldn't reject his offer like he'd done more times in the past than he'd accepted it.

"I don't want to impose…" Mob said trailing off, and Ritsu's heart skipped a beat - any and all lack of outright 'no' when it came to Mob was a 'yes'.

"I wouldn't have offered if I thought you were going to be," Ritsu lied with a soft laugh. "Plus, helping you study for your entrance exams will give me a head start on mine next year." Not that he needed it when he was already one of the top of the nation, but sometimes helping Mob required a little bit of manipulation, tricking him into thinking he was helping Ritsu when really it was the other way around.

At long last, Mob pulled his face out of Ritsu's neck and sat back, though his head remained bowed. The shift in weight and in muscles around his knot sent more heat up Ritsu's spine, though this time he hid the tremor in his fingers by lifting them from Mob's back and settling them on his brother's thighs. And when Mob didn't immediately speak, Ritsu gave into temptation to dip down and press his lips to Mob's, immediately feeling vindicated when his omega's mouth opened to him and he licked his way inside.

As always, Mob's tongue was hesitant against his, but Ritsu was well accustomed to his brother's tentative affection. All he had to do was kiss slow and deep and soft and Mob melted against him, hands finally lifting from where they hung at his sides to press against Ritsu's ribs, fingers curling carefully into his shirt as if Mob was afraid the cotton was going to rip.

When he finally pulled away, only far enough to separate their mouths but still close enough that he could press his forehead to Mob's, his brother finally looked him in the eye. It was a shy contact, as shy as the smile that curved his omega's soft mouth, but they were there are all the same, and that was enough for him.

"Thank you, Ritsu," Mob finally agreed.

By now, Ritsu was an expert in all the things his brother didn't say, and he knew it wasn't just his study assistance that he was being thanked for.

"Of course, nii-san," Ritsu assured, sitting back and pulling Mob back into his chest, his omega's nose settling in against his throat. "Any time."

Mob fell asleep almost before Ritsu had finished speaking, breath slow and steady against his neck as Ritsu reached for his discarded book. It had only been a week since Ritsu had knotted his omega last, but maybe that was too long if his brother was this tired and this stressed. Maybe it was time to start knotting Mob every night, see if that helped. He turned the page and settled in for the long haul, wrapping his free arm around his brother, tucking the tips of his fingers in the waistband of Mob's shorts to keep his hand anchored at the small of Mob's back. Against his throat, Mob snuffled sleepily, relaxing further into Ritsu's body, and Ritsu began to purr.

Maybe before they started studying, he should knot his mate again.

One more time.

...Once or twice.

Just in case.

FIN

* * *

**So, just like last chapter, I don't have any _plans_ to write more, but apparently all I have to do is see an art and one of my muses will just fucking slap me.**

**Don't forget: ****Like the thing? Reblog the thing (themadkatter13fanfiction tumblr, tagged/Brother (Mine)).**


End file.
